function wymiary(ktory_wymiar){
	var x,y;
	
	// all except Explorer
	if(self.innerHeight){
		x = self.innerWidth;
		y = self.innerHeight;
	}
	// Explorer 6 Strict Mode
	else if(document.documentElement && document.documentElement.clientHeight){
		x = document.documentElement.clientWidth;
		y = document.documentElement.clientHeight;
	}
	// other Explorers
	else if(document.body){
		x = document.body.clientWidth;
		y = document.body.clientHeight;
	}
	
	if(ktory_wymiar == 'x' || ktory_wymiar == 'y'){
		return eval(ktory_wymiar);
	}
	else{
		return x+','+y;
	}
}

function unormuj_srodek(){
	var e = document.getElementById("srodek");
	var min_y = wymiary('y') - 210;
	
	if(e.style.height < min_y){
		e.style.height = min_y;
	}
}

function window_open(url, name, feat){
	window.open(url, name, feat);
}

function pokaz(element_id){
	var e = document.getElementById(element_id);
	e.style.visibility = 'visible';
}

function ukryj(element_id){
	var e = document.getElementById(element_id);
	if (e.style.color != 'black') {
		e.style.visibility = 'hidden';
	}
}